The present invention is related to an industrial truck with a load supporting means. The industrial truck is equipped with a sending and receiving unit, the sending and receiving range of which is directed towards a region of the load supporting means and towards a region in front of the load supporting means.
It is known that in the data exchange via RFID sending and receiving units, a transmission shortage may occur by reason of a multiplicity of such units and transponders in one room, because available wireless channels are not sufficiently at hand. For the simultaneous operation of many sending and receiving units, in a storeroom for instance, it is therefore aimed at limiting the activation thereof as far as possible.
A possible concept to limit the activation of the sending and receiving units is to have the activation performed by the operator, depending of the situation. In doing so, the operator can trigger the activation of the sending and receiving unit in order to activate a transponder in the sending range and to receive its emitted data. However, in this concept it is a disadvantage that the operator may forget the actuation and/or activate the sending and receiving unit unnecessarily frequently.
From US 2006/058913, the entire contents of which is incorporated herein by reference, an industrial truck is known which is equipped with gripping means for a cuboid-shaped load. The gripping elements, equipped with a flat contact wall are equipped with RFID sending and receiving units. Further, it is known to trigger the reading process of the sending and receiving units when an internal pressure sensor of the gripping elements acquires a sufficient holding pressure at the gripping elements.
From EP 1 444 647 B1, the entire contents of which is incorporated herein by reference, an industrial truck is known which uses an array of RFID reading antennas along the mast of a load supporting means. The load supporting means is equipped with a distance sensor, which measures the distance to the nearest object. When this distance falls below a predetermined minimum value, a reading process is actuated for the RFID antennas.
The present invention is based on the objective to perform the activation of a sending and receiving unit with as simple as possible means at small expense for upgrading and installation.